Proportioning pump



Aug. 13, 1963 Filed Jan. 24. 1961 I A. S. LIMPERT ETAL PROPORTIONING PUMP 2 Sheets-Sheet 1 BYW PPM

Aug. 13, 1963 A. s. LIMPERT ETL PRoPoRTIoNNG PUMP 2 Sheets-Sheet 2 Filed Jan. 24, 1961 United States Patent O This invention relates to chemical feeder pumps, and more particularly to an improved form of hydraulically actuated metering pump.

Metering pumps are commonly employed for injecting measured quantities of liquid chemical or other potent` liquid into a flow or substrate, as for example, when chlorinating water entering a swimming pool or adding reactants to a stream of chemical soltuion. The rate of flow of such substance moved by the pump is required to be definitely determinable, is usually adjustable to precisely predetermined values, and frequently is automatically so adjusted to correspond with the flow of substrate and thus provide a so-called proportioning pump.

It has been found advantageous to construct such metering pumps for hydraulic actuation from a separate motorized pulsing unit, as set forth in our patent for Liquid Proportioning Pump, Patent No. 2,869,467, dated Janu-` ary 20, 1959, where there is disclosed a diaphragm type of chemical pumping unit for actuation by hydraulic pulsmg means.

The present invention contemplates the provision of an improved pumping unit for hydraulic actuation whereby certain economies of construction and improvement of operation are obtained through the use of a double diaphragm type of pump construction and other inventive features.

An object of the invention is therefore to provide a pump having increased pumping capacity for the same size pump.

Another object is to provide a metering pump having minimum head space or clearance volume.

Another object is to provide a metering pump which is easy to clean.

` Another object is to provide a pump which requires a minimum of expensive iittings in its construction.

Another object is to provide a pump wherein reduced diaphragm diameter obviates the need for bulky construction in a high pressure pump.

These and other objects of the invention are achieved by the use of va pumping chamber in the form of a cylinder closed at each end by an impermeable exible diaphragm, which diaphragms are backed by pressure plates to form a hydraulically actuable pumping system having an internal hydraulic passage interconnecting the space between each diaphragm and its corresponding backing plate.

It will be observed that it is thus possible to double the volumetric einciency of the pump Without at the same time materially increasing its complexity because of the fact that an auxiliary hydraulic pulsing unit as described in the 'above mentioned patent can still be used to actuate the metering pump without change. I-t would of course, be exceedingly diiiicult, and probably impractical to attempt to actuate a pump having double diaphragm construction with opposed diaphnagms by other than hydraulic means because of the mechanical complexity of the necessary linkages involved.

A clearer understanding of the invention may be obtained from the following detailed description of an illustrative example of a preferred form thereof taken in conjunction With the drawings, wherein: v

1 is an elevation of a metering pump constructed in accordance with the present invention;

PIG. 2 is a sectional vie-W taken on the line 2 2 of \FIG. 1;

FIG. 3 is a sectional view taken on the line 3-3 of FIG. 2;

FIG. 4 is an exploded View of FIG. 2 showing the component parts before assembly;

FIG. 5 is an exploded View of an alternative subassembly of FIG. 2;

FIG. l6 is a View of an alternative sub-assembly of `FIG. 2; and

IFIG. 7 is a view of an alternative sub-assembly of FIG. 2.

Referring now to the drawings in which like numbers refer to like parts throughout there is seen in FIG. 1 a base lil carrying a motor rotated flywheel 1-2 connected by a yoke 13 to an adjustable hydraulic pulsing mechanism 14 of the kind described in our aforementioned Patent No. 2,869,467 whereby reciprocating pulsations of hydraulic fluid having a definite and controlled displacement and periodicity yare produced in the hydraulic line 15 to the diaphragm pumping unit `lr6 which is seen more clearly in FIG. 2.

A backing plate 17 has a compression fitting 18 secured by a pipe thread into a tapped hole in said plate, and by means of compression nut 21 retains hydraulic line 415 in communication with a recess 22 in plate 17. Said recess 22 also communicates by means of drilled Channels such as 23 and 24 vwith a similar recess 25 in an opposing backing plate 26. Backing plates 26 and 17 are secured in place by means of through bolts such as 28 seen also in FIG. 3, provided with nuts 29, and have bosses 31 and 32 adequate to provide a thickness of material sutlicient to safely accommodate the application of fittings and the drilling of interconnections aforementioned.

Said backing plates are so secured over an annular pump chamber 27 which may be seen more clearly in the exploded view of FIG. 4. As there are shown, the member 27 has recessed portions such as 33 on either side thereof rand is covered on either side by the diaphragms 34 and 35 before the plates 17 and 26 are bolted in place thereover.

Also inserted therebetween before such closure are the cheeks 36 and 37 and the compression spring 38 therebetween. The function of the latter is to distend the diaphragms 34 and 35 in the quiescent condition when a hydraulic pulse is not being applied, and thus assist in filling the pump chamber 39 of FIG. 2 on the back stroke of the pump, thereby avoiding the need of negative pressure in the hydraulic system, and obviating the possibility of entraining undesired leakage bubbles of air therein. Such entrainment could occur in a hydraulic system which is nevertheless tight to hydraulic Huid because of the great disparity between the 'viscosity of air and that of hydraulic fluid, whereby air can enter apertures and seals which are still of ample tightness to prevent the escape of such media as hydraulic iuid.

it is convenient and desired to construct the operative parts of the described pump assembly, as well as those parts further to be described, of materials highly resistant to corrosion such as inert plastic polymers, and in the case of the spring 38, of stainless steel. Plates 17 and 26 are conveniently made of metal, while member 27 may be transparent plastic and diaphragms 34 and 35 of tough material -such as a iiuorinated hydrocarbon polymer.

Appropriate inlet and outlet valves 41 and 42, provided with annular seal rings` 43 and 44 respectively are contained in valve chamber 45 and valve chamber cover 46 respectively, into which pump inlet and outlet tubes 47 and 48 are secured by compression screws 49 and 51 v27 which communicate with the pump chamber 39 of FIG. 2.

In FIG. 5 there is shown an alternative construction of the cheek and spring elements for diaphragm distention above described, wherein cheeks 56 and 57 are resiliently as rubber or synthetic' rubber.

`In FIG. 6 there is shown another form of diaphragm distending device 59 wherein the elastomeric block 61 provides a unitary construction with the integral cheeks 62 and 63.

In FIG. 7 there is shown another form of diaphragm distending device 64 wherein an elastomeric block 65 is formed integral with a single cheek 66 for cooperation with a corresponding plain cheek not shown.

I-t will be observed that the structures shown in FIGS. S, 6, and 7 are especially adapted for use in double diaphragm pumps of the instant construction. Also, they provide the advantages of overcoming metal fatigue in la spring, reduction of clearance volume, and in FIG. 6, the elimination of crevices for easy cleaning and in FIG. 7 a construction which, because of its freedom from undercut, is adapted for ready moldability.

When a resilient member such as shown .at SS, 61 or 65, which is composed of an inherently resilient substance, is used, it is possible so to design the volume v separated -by the block S8 of elastomeric material such Y and elasticity thereof that it is almost fully equal in volume to the volume of the pump chamber when contracted. Under this condition the member is squeezed by the hydraulic driving pulses in a iiattening manne-r, to nearly iill thepump chamber, in which case the volumetricgeiiiciency of the pump can Ibe made to .approach one hundred percent. This is advantageous both in priming under high lift conditions, and in the accurate haudling of fluids likely to separate in phase under conditions of reduced pressure, such as volatiles, gas solutions, or substances in which small quantities of foam may be entrained or entrapped.

The construction of the instant invention as above described is further advantageous over any attempt to use two pumps for the same purpose as a double diaphragrn pump, for the reason that but a single resilient element is used for returning the diaphragms to the quiescent position. rial and complexity involved, it is further found that when two `diaphragms are employed, it becomes impractical to provide them with independent resilient members because of the fact that it is then exceedingly diflicult to cause them to equally divide the pumping load. Obviously, if two diaphragme are to beemployed, itis imperative that they undergo approximately equal exure during pumping in order that the operating life of the diaphragms will not be vunduly shortened. lf separate springs are used for the two diaphragms, the springs must have tensions which are both initially and permanently almost exactly equal. It is possible but costly to select springs so that they will initially provide the same tension, but no way is known to ensure that they will remain so indenitely. This diiiiculty is entirely overcome by the present invention, wherein the tension of a single `resilient member is shared by both diaphragms.

v lAn additional advantage of the instant invention resides in the fact that the reduced clearance volume made possible principally by the double diaphragm construction causes the pump to lbe especially effective during the initial priming operation, and in fact causes it to provide a lift or suction pressure of marked superiority over that obtainable from other constructions.

Although4 this invention has been described in terms Vof a speciiic illustrative example thereof, it will be readily understood that various modifications or elaborations will occur to those skilled in the art, and it is therefore intended that the invention shall be limited only by the f appendedV claims.

What is claimed is:

1. In a feeder pump for hydraulic pulsing, an apertured cylindrical body of relatively rigid material having a hydraulic passageway therethrough, iiexible diaphragme covering the ends of said body and having openings aligned `with said passageway, rigid cover plates cover.- ing the ends of sa-id body and the said diaphragms and having recessed portions on the interior faces thereof communicating with said passageway and having at least one exterior opening for energization, through bolts pass ing between said cover plates and through said body and said diaphragrns for securing them rigidly together, an inlet and an'outlet valve chamber, located one in each of said apertures, a valve freely movable in each said valve chamber, and a toroidal washer of resilient material on each said valve, and resilient compressible means located between said diaphragms for applying dilating pres-V sure lthereto and comprising a pair of recessed cylindrical and diaphragm contacting cheek pieces and a compression spring located therebetween and in the recesses.

2. In a :feeder pump for hydraulic pulsing, an apertured body of relatively rigid material having a hydraulic passageway therethrough, flexible diaphragms covering the ends of said body and having openings aligned with said passageway, rigid cover plates covering the ends of said body and the said diaphragms and having recessed portions on the interior faces thereof communicating with said passageway and having at least one exteriorropening for energization, means passing between said cover plates and through said body and said diaphragms for securing them rigidly together, and an inlet and .an outlet valve chamber, located one in each of said apertures, a

, valve freely movable in each of saiid valve chamber, and a tiexible washer of resilient material on each said valve,

and resilient compressible means located between said diaphragms for applying dilating pressure thereto and comprising a` pairof recessed cylindnical and diaphragm contacting cheek pieces and a compression spring located therebetween and in the recesses.

yAside from the obvious saving in mate- 3. In a Ifeeder pump for hydraulicpulsing, an apertured body of relatively rigid material having a hydraulic passageway therethrough, flexible di-aphragms covering the ends of saiid body and having openings aligned with.

said passageway, rigid cover plates covering the ends of said body and the said diaphragms Vand having recessed portions on the interior faces thereof communicating with said passageway and having at least one exterior opening for energization, means passing between said cover plates and through said body and said diaphragms `for securing them rigidly together, and an inlet and an outlet valve chamber, located one in each of said apertures, a valve freely movable in each sm'd valve chamber, and a washer of resilient material on each said valve, and resilient compressible means located between said diaphragms for applying dilating pressure thereto and comprising Ia pair of recessed cylindrical and diaphragm contacting cheek pieces and a homogeneous resilient compressible member located therebetweenv and in the recesses.

4. 4In a feeder pump for hydraulic pulsing, an apertured body of relatively rigid material having an hydraulic passageway therethrough, iiexible diaphragme covering the ends of said body and having openings aligned with said passageway, rigid cover plates covering the `ends of said body `and the said diaphragms and having recessed portions on the interior faces thereof communicating with said passageway and having at least one exterior openingV for energization, means passing between said cover plates and through said .body and said diaphragmsjfor securing them rigidly together, and an inlet and an outlet valve chamber, located one in each of said apertures, a valve freely movable in each said valve chamber, and a toroidal washer of resilient material on each said valve, and resilient compressible means located between said diaphragrns for :applying dilatin-g pressure thereto.

(References on foilowing page) References Cited in the le of this patent UNITED STATES PATENTS Waseige Dec. 8, 11931 Herbert May 7, 1946 Egerer oct. 30, 19656 5 Limpert et al. Jan. 20, 1959 6 Wiggermann Jan. 5, 1960 FOREIGN PATENTS Australia Nov. 21, 1957 France June `f14, 1940 Great Britain Dec. 4, 1930 

1. IN A FEEDER PUMP FOR HYDRAULIC PULSING, AN APERTURED CYLINDRICAL BODY OF RELATIVELY RIGID MATERIAL HAVING A HYDRAULIC PASSAGEWAY THERETHROUGH, FLEXIBLE DIAPHRAGMS COVERING THE ENDS OF SAID BODY AND HAVING OPENINGS ALIGNED WITH SAID PASSAGEWAY, RIGID COVER PLATES COVERING THE ENDS OF SAID BODY AND THE SAID DIAPHRAGMS AND HAVING RECESSED PORTIONS ON THE INTERIOR FACES THEREOF COMMUNICATING WITH SAID PASSAGEWAY AND HAVING AT LEAST ONE EXTERIOR OPENING FOR ENERGIZATION, THROUGH BOLTS PASSING BETWEEN SAID COVER PLATES AND THROUGH SAID BODY AND 